Does that mean they have to come up with their own taxes? Are they cut off from the federal dole? How ever will they exist on their own?
Well, the State of DC will get 3 Electors as a result of being a State, but the 3 Electors Congress awarded DC in 1960 with Amendment XXIII won't go away.
There will still have to be a Federal District, most DC statehood schemes admit this.
That rump Federal District will still have residents - Joe, Jill, Kamala, and Douglas, at least.
Will those four individuals get 3 Electors?
Let's read the Constitution:
"The District constituting the seat of government of the United States shall appoint in such manner as the Congress may direct: A number of electors of President and Vice President equal to the whole number of Senators and Representatives in Congress to which the District would be entitled if it were a state, but in no event more than the least populous state; they shall be in addition to those appointed by the states, but they shall be considered, for the purposes of the election of President and Vice President, to be electors appointed by a state; and they shall meet in the District and perform such duties as provided by the twelfth article of amendment.
So it sounds like Joe, Jill, Kamala and Douglas will be appointing 3 Electors in 2024, all on their own.